Smart Shunt (500A) Has 10-15% SOC variance regardless of settings changed

[pwfarnell]

If you have the charged voltage on the shunt set to 13.4V and the MPPT absorption set to 14.25V then the MPPT will raise the voltage above 13.4V with very little current at dawn or on cloud edge. If you have solar you MUST set the charged voltage on the shunt 0.1 to 0.2V below the MPPT absorption voltage.. Really a bad idea to have 2 chargers with significantly different absorption voltages. If you leave the WFCO at 13.6V with a charged voltage on the shunt of 14.15V then when that is charging it will not synchronise but will still count in the Ah and return to a high value. Personally, I would set the WFCO to charge at the same as the Mastervolt recommendations.

Battery monitor jumping to 100% or reporting a high SOC with low Volts / the BMS shuts down

This topic covers the reported SOC being out of sync with the actual battery voltage or state. It covers BMV battery monitors, SmartShunts, Lynx BMSs and Lynx Shunts and will just be called shunt below. It is also assumed that the shunt is monitoring the domestic / house / cabin battery bank and not engine start / bow thruster / winch / caravan mover battery banks. The problems may be one or more of the following and is often linked to mobile applications with small solar systems. The SOC jum…